xref: /openbmc/linux/fs/nls/nls_utf8.c (revision 588b48ca)
1 /*
2  * Module for handling utf8 just like any other charset.
3  * By Urban Widmark 2000
4  */
5 
6 #include <linux/module.h>
7 #include <linux/kernel.h>
8 #include <linux/string.h>
9 #include <linux/nls.h>
10 #include <linux/errno.h>
11 
12 static unsigned char identity[256];
13 
14 static int uni2char(wchar_t uni, unsigned char *out, int boundlen)
15 {
16 	int n;
17 
18 	if (boundlen <= 0)
19 		return -ENAMETOOLONG;
20 
21 	n = utf32_to_utf8(uni, out, boundlen);
22 	if (n < 0) {
23 		*out = '?';
24 		return -EINVAL;
25 	}
26 	return n;
27 }
28 
29 static int char2uni(const unsigned char *rawstring, int boundlen, wchar_t *uni)
30 {
31 	int n;
32 	unicode_t u;
33 
34 	n = utf8_to_utf32(rawstring, boundlen, &u);
35 	if (n < 0 || u > MAX_WCHAR_T) {
36 		*uni = 0x003f;	/* ? */
37 		return -EINVAL;
38 	}
39 	*uni = (wchar_t) u;
40 	return n;
41 }
42 
43 static struct nls_table table = {
44 	.charset	= "utf8",
45 	.uni2char	= uni2char,
46 	.char2uni	= char2uni,
47 	.charset2lower	= identity,	/* no conversion */
48 	.charset2upper	= identity,
49 };
50 
51 static int __init init_nls_utf8(void)
52 {
53 	int i;
54 	for (i=0; i<256; i++)
55 		identity[i] = i;
56 
57         return register_nls(&table);
58 }
59 
60 static void __exit exit_nls_utf8(void)
61 {
62         unregister_nls(&table);
63 }
64 
65 module_init(init_nls_utf8)
66 module_exit(exit_nls_utf8)
67 MODULE_LICENSE("Dual BSD/GPL");
68